The fabrication of nanolines of very small widths is important for several emerging device applications. For example, in the molecular electronics field, the banded energy states of single molecules can be electrically manipulated to achieve a variety of discrete nano-scale devices such as non-linear resistors, switches, and transistors, as well as electrically settable, readable, and resettable memory cells. However, to harness the promising potential of such nano-scale devices, it is necessary to provide meaningful electrical access to them from outlying macro-scale and micro-scale environments. For example, in producing an ultra-dense memory device, it would be desirable to produce a large-scale array of metallic nanolines, also termed metallic nanowires, nanotraces, or nanoconduits, having line widths of 10 nm or less. Decreasing the line widths even further can result in even higher memory densities, even down to 1 nm or less in some cases before other factors begin to limit achievable densities.
Due to substantial difficulties with photolithographic methods below about 100 nm, and due to production scalability problems with electron beam lithography methods, one method for achieving scalable device production for line widths below 50 nm is to use electron beam lithography to pattern a nanoimprint mold, and to transfer the imprinted pattern to target production devices according to a nanoimprint lithography process. However, electron beam lithography itself is generally limited to the 20 nm-30 nm range due to feature broadening from secondary electron yields (proximity exposure). Even using a spatial frequency doubling technique to further increase resolution, electron beam lithography is generally limited to the 10 nm-15 nm range.
It would be desirable to produce a dense array of nanolines in a manner that allows for line widths below 10 nm, while also allowing for per-line connectivity to a nearby array of lesser density, thereby facilitating external access to the dense array. More generally, it would be desirable to provide an array of nanolines in a manner that allows for line widths below 10 nm while also allowing for lengthwise-varying pitch.